Field of the Invention
The present invention relates to a motor, and more particularly, to a brushless motor having a stator combined with a rotor.
Technology Background
A motor may comprise a rotor having a plurality of magnets and a stator having a core and a winding on the core defining a plurality of coils. Such motors may be divided into fractional-slot winding motors and integral slot winding motors depending on the winding configuration in the winding. A fractional-slot winding motor greatly reduces slot area occupied by an insulation bracket, thereby improving a slot fill factor of the winding, reducing winding resistance, and improving motor efficiency.
However, in a related art fractional-slot winding motor, the armature reaction has increased amounts of higher harmonics, which leads to the increase of motor iron loss. Further, the asymmetry of magnetic circuit easily causes partial magnetic saturation, which leads to motor vibration and increased noise.